1. Field of the Invention
This invention relates to removable storage media cartridges. More particularly, this invention relates to a secondary optical storage medium in a removable storage media cartridge accessible by both the accessor and the drives of an automated storage library.
2. Description of the Related Art
Automated data storage libraries are known for providing cost effective storage and retrieval of large quantities of data. The data in automated data storage libraries is stored on removable storage media that are, in turn, stored on storage shelves or the like inside the library in a fashion that renders the media, and its resident data, accessible for retrieval. Such media is commonly termed “removable media.” Removable storage media may comprise any type of media on which data may be stored and which may serve as removable media, including but not limited to magnetic media (such as magnetic tape or disks), optical media (such as optical tape or disk), holographic media, electronic media (such as PROM, EEPROM, flash PROM, Compactflash™, Smartmedia™, Memory Stick™, etc.), or other suitable media. Typically, the data stored in automated data storage libraries is resident on removable storage media that is contained within a cartridge and referred to as a removable storage media cartridge. An example of a removable storage media cartridge that is widely employed in automated data storage libraries for mass data storage is a magnetic tape cartridge.
In addition to removable storage media, automated data storage libraries typically contain data storage drives that store data to, and/or retrieve data from, the removable storage media. The transport of removable storage media between data storage shelves and data storage drives is typically accomplished by one or more robot accessors or pickers (“accessors”). Such accessors have grippers for physically retrieving the selected removable storage media from the storage shelves within the automated data storage library and transporting such media to the data storage drives by moving in the X (horizontal) and/or Y (vertical) directions. Depending on the library design, more complicated movement may include a Z direction and even radial movements of the gripper.
However, while the removable storage media is stored on a shelf or storage cell, the data is inaccessible. Currently, a removable storage media cartridge typically has the primary data storage media, or if a secondary data storage media is also included with the primary data storage medium, the secondary storage medium is electronic media or the like with a relatively small data storage capacity. The primary storage media is typically used to store the actual data. The secondary storage media can be used to store meta information about the cartridge and the data on it. Typical meta information about the cartridge and the media is the volume serial number (VOLSER), tape directory, media error statistic. For a removable storage media with no secondary memory, whenever the slightest bit of information is needed, the removable storage media must be physically moved from its storage cell to a data storage drive to be mounted and accessed. This is a time consuming process that requires the resources of the robotic accessors and therefore slows read and write requests from a host machine. Simple maintenance operations such as media inventory or reading the directory require that every removable storage media be removed from the storage cell and placed in an available drive to be accessed. Depending on the number of available accessors and drives, the inventory may cause the automated storage library to go offline for several hours. More often required meta information is the VOLSER (inventory) and the media error statistic for predictive maintenance.
A removable storage media with an electronic secondary storage medium or the like allows data such as directory information to be stored on the secondary media. Storing data on an electronic storage media is advantageous in that an accessor or other means can be used to determine the contents of the removable storage media or other pertinent information stored on the electronic storage media without retrieving the removable storage media and placing it in an available drive. However, the minimal storage capacity of the electronic secondary storage media greatly limits its functionality.
When removable storage media without a secondary storage is used in a data drive in a server or other computer, accessing the data may be slow and cumbersome. A user may have to access the primary storage media to determine directory information, data types, file names, or other useful information. Accessing the primary storage media may be much slower than accessing the same information on a secondary storage medium. If an electronic secondary storage medium is included on removable storage media, a server may be able to access some data from the electronic secondary storage medium, but the capacity is limited.
From the foregoing discussion, it should be apparent that a need exists for an apparatus, system, and method for a secondary optical storage medium in a removable media storage cartridge. Beneficially, such an apparatus, system, and method would allow data to be stored on a secondary optical storage medium in a removable media storage cartridge with a higher capacity than currently available electronic secondary storage medium and would allow access of data on the secondary optical storage medium without placing the removable media storage cartridge in an available drive. For example the cartridge accessor can read the meta information from the secondary optical storage medium though an appropriate system making it unnecessary to place the cartridge in a drive.